a polymer of glucose residues linked by alpha 1-4 and alpha 1-6 linkages

Glycogenolysis

The breakdown of glycogen

Glycogen Phosphorylase

releases a G1P if it is at least 5 units away from a branch point

Glycogen Debranching Enzyme

removes branches making more residues available to glycogen phosphorylase, transders alpha 1-4 trisaccharides from a limit brancce to the non reducing end of another branch and hydrolyzes the alpha 1-6 glycosidic linkage

Phosphoglucomutase

G1P to G6P

Liver

Regulates a constant supply of glucose

How is glucose generated in the liver

G6P to glucose by G6Pase

what do muscles and other tissues not have that causes them to retain glucose

G6Pase

Where is G6Pase located and how does G6P get there?

G6Pase is in the ER and G6P gets there through a translocator

How does glucose leave the liver

GLUT2

What is McArdel's Disease

McArdel's Disease is when individuals lack muscle glycogen phosphorylase but their muscles still contain high levels of glycogen

UDP-glucose phosphorylase

combines G1P with UTP to produce UDP-glucose

Glycogen synthase

transfers a glucose unit from UDP-glucose to the non-reducing end forming an alpha 1-4 glycosidic linkage. This enzyme can only extend already existing chains

How is UTP replenished

Nucleoside Phosphate Kinase

Glycogen Branching Enzyme

amylo-1,4-1,6-transglycosylase, creates branches by taking a 7-residue segment from the end of a chain to a C6OH and this segment must come from a chain that is at least 11 units long so that the new branch can be 4 residues away from the last one

What is chain formation initiated by?

Glycogenin

Glycogen Phosphorylase requires ________

pyridoxal-5'-phosphate which has R (active) and T (inactive) conformations

What inhibits Glycogen phosphorylase

high ATP, G6P, and glucose

What activates glycogen phosphorylase?

high AMP

What are the two forms of glycogen phosphorylase?

phosphorylated form, a, is more active

unphosphorylated form, b, is less active

What is glycogen synthase inhibited by?

AMP

What is glycogen synthase activated by?

ATP and G6P

What are the two forms of glycogen synthase?

phosphorylated, b, less active

unphosphorylated, a, more active

What role does Protein Kinase A play in glycogen synthesis

Protein Kinase A activates glycogen phosphorylase a which with calcium inactivates glycogen synthase